Freezing apparatus

Abstract

The invention provides a freezing apparatus. When the high pressure side is up to a critical pressure, a compression mechanism can be prevented from being influenced by the high pressure, and the freezing capacity of the freezing apparatus can be prevented from being influenced by outside air temperature. The freezing apparatus comprises an electric expansion valve (33) that is connected to the downstream side of an air cooler (28) and the upstream side of an electric expansion valve (39); a casing (36) that is connected to the downstream side of the freezing apparatus and the upstream side of an electric expansion valve (39); a separating heat exchanger (29) that is set at the downstream side of the freezing apparatus and the upstream side of an electric expansion valve (39); an auxiliary circuit (48) that helps a refrigerant in the casing flows from electric expansion valves (43,47) into the separating heat exchanger, and then into the middle compression part of a compressor (11); and a main circuit (38) that helps the refrigerant flows from the lower part of the casing into the separating heat exchanger , and flows into the electric expansion valve (39) after heat exchange with the refrigerant flows in the first path; and a control apparatus (57) adjusts the pressure in the high pressure side of the refrigerant loop at the upstream side through the electric expansion valve (33).

Description

Technical field [0001] The invention relates to a refrigeration device in which a compression mechanism, a gas cooler, a main throttling mechanism and an evaporator constitute a refrigerant circuit, and the high pressure side reaches a supercritical pressure. Background technique [0002] In the past, this type of refrigeration device constitutes a refrigeration cycle by a compression mechanism, a gas cooler, a throttle mechanism, etc. The refrigerant compressed by the compression mechanism radiates heat in the gas cooler, and is decompressed by the throttle mechanism, and then used in the evaporator. The refrigerant evaporates, and the evaporation of the refrigerant at this time is used to cool the surrounding air. In recent years, Freon-based refrigerants have gradually ceased to be used in such refrigeration devices due to natural environmental problems. Therefore, the use of carbon dioxide as a natural refrigerant as a substitute for Freon refrigerant is being developed. It...

AI Technical Summary

Problems solved by technology

[0004] On the other hand, for a refrigeration device installed in an evaporator such as a showcase to cool the inside of the cabinet by using heat absorption, the temperature at the outlet of the gas cooler is high due to the high temperature of the outside air (the temperature of the heat source on the side of the gas cooler). When the temperature of the refrigerant increases, the specific enthalpy at the inlet of the evaporator increases, so there is a problem that the refrigeration capacity drops significantly

At this time, if the discharge pressure (high pressure side pressure) of the compression mechanism is increased in order to ensure the refrigeration capacity, the compression power will increase and the coefficient of performance will decrease.

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